Improvement in electric telegraphs



3 Sheets-Sheet l.

M. G. PARMER. ELECTRIC TELEGRAPH.

' Patented Mar. 29; 1858.

3 Sheets-Sheet 3.

M. G. FARMER. ELECTRIC TELEGRAPH.

No. 9,634. Patented Mar. 29, 1858.

UN TED STATES PATENT OFFICE.

MOSES Gr. FARMER, 0F SALEM, MASSACHUSETTS.

IMPROVEMENT IN ELECTRIC TELEGRAPHS.

I Specification forming part of Letters Patent No. 9,634, dated March29, 1853.

To all whom it may concern.-

Be it known that I, MOSES GsFARMER, of Salem, in the county of Essex andState of Massachusetts, have invented a new and useful ImprovementinElectric Telegraphs, which Iterm the Synchronous Telegraph and I; dohereby declare that the same is fully described and represented in thefollowing specification and the accompanying drawings, letters, figures,and references thereof.

The object of my invention is to enable a common telegraphic circuitextending between any two places to be used by two or more operators atthe same time, instead ofbut one operator, as it is at present; or, inother words, suppose that we are to have tour operators stationed at oneend of the line and each conducting or operating a signal key orinstrument for breaking or closing the circuit, also that we wish tocommunicate with fourpcrsons at the other end of the line by means-offour signalinstruments there placed, we make use of two wires betweenthe two places. One of these wires is used for the purpose ofconveyingthe communication between the two places. It may be termed theprimary or writing wire or line. The other wireor line,and whichmay betermed the secondary wire or main line for working,is used to bring thefourinstrumeuts at each station into alternate communication with thecommon communication or primary wire in the following mannerthat is tosay: Let the instruments atone of the stations be numbered 1 2 3 4 andthose at the other station be numbered 1 2 3 4. Now, by the action ofmachinery, No. l at one station or termimus of the line will be inconnection with the common communication-wire for an instant preciselyat the time that No. l at the other station or terminus will be inconnection with the samewire. The two instruments Nos. 1 and 1 at bothplaces will therefore be in communication with one another for suchbriefinstant of time. At the next instant the No. 2 at one station andNo. 2 at the other will be put in connection with the common wire, andof course with one another, the Nos. 1 and 1' having been thrown out ofconnection therewith. During the next instant Nos. 3 and 3 will be putin connection with the common wire and with each other, the other wiresbeing out of connection therewith. During the next instant Nos. 4 and 4will be put in like connection with the com monwire and each other.During the fifth instant Nos. 1 and 1 will be again put in connectionwith each other, and thus, in regular succession, corresponding numbersare put in connection with the primary wire and with each other. If,therefore, these connections are made to rapidly recur-say at the rateof about twenty per secoud-each of the four instruments at one end of aline will seem to be in-constantconnection with its fellow number at theother end thereof, and willhave' no connection with any other instrumentwhile the machinery keeps in adjustment. Should by any means theadjustment of the machinery become deranged, I have the necessary meansat hand to readjust it, and this in a second or two of time, all ofwhich will be hereinafter particularly explained.

Of the drawings above mentioned, Figure 1 represents a top view of mysaid synchronous telegraph. Fig. 2 is a side elevation of one of themachines 'stationed at each terminus. Fig. 3 is an elevation of theother side of it. Fig. 4 is a vertical central and longitudinal sectionofit. Fig. 5 is a'transverse section of it-as taken through theescapementwhcel and circuit-wheels to be hereinafter described, and aslooking toward what are hereinafter termed the two local magnets. Fig. 6is another transverse and vertical section, taken through the column orpost that supports the springs of the circuit-wheels, said figure beingmade to exhibit the magnet ot' the primary circuit, its vibrating orpendulous armature, and the screws thereof at the opposite end of themachine.

The synchronous machine, at one terminus of the telegraph is identicalwith that at the other terminus. One of these machines in Fig. -1 ismarked A and the other B. In de scribing one machine I thereforedescribe the other. It consists, in general, of an escapewheel, G, somepower actuating this wheel or giving it a tendency to rapidly rotate,necessary detents toarrest and keep up the motion of this wheel, andsome apparatus to control the action of the said detents, so that thedetent of one of the synchronous machines shall move at precisely thesame instant and in the same manner as does the corresponding detent ofthe other machine at the other terminus of the telegraph. By this meansthe motions of one escape-wheel will be the same or synchronous withthose of the other. If the detentsare moved by the action ofelectromagnets, the opening and closing of the electric' circuit inwhich said magnets are placed will cause the movements of the two wheelsto take. place at the same time. In the particular machine before us theescapementwheel Ois made with fourteen teeth. ;Itis operated by twoindependentpallets, D E, that are made to respectively project from twovibrating levers, F G, that turn on fulcra at their'lower ends, and

have armatures H I arranged between said 7 fnlcra and the pallets, asseen in the drawings. To each lever a spring, K or L, is applied andmade to operate in such manner as to draw the pallet 'of such levertoward and against the escapement-wheel. The pallet is thus, by theforce of a spring, drawn against the inclined plane or edge of a toothof the escapementwheel, and tends to push the wheel forward or give to,it a. rotation in the direction of the arrow a. While one pallet is atthe bottom of a tooth the other is acting on the opposite edge of thetooth, and at about midway of the depth of the tooth, and by itspressure against such edge of the tooth it will cause the wheel torevolve when the other pallet is next drawn away from it. The pallet,however, which is at the bottom of a tooth or in the vertex of the angleof the two consecutive teeth, acts a ainst a steeper inclined plane, asit were, an in an opposite direetioin'and while in such positionv iteffectually opposes the motion of the wheel.

These pallets are so adjusted that when one" at the bottom and againstthe side of a tooth is pulled away from the wheelthe other, pressing onthe side of the next tooth, turns the wheel until it (the pallet)reaches the bottom of such tooth, and at the same time carries the wheelaround far enough-to allow the first pallet on its return toward thewheel to pass over the point and on the other side of the tooth againstwhich it before rested.

With respect to the relative adjustment of this arrangementtotheinstants of closing and breaking the circuit, itmay be remarked thatit should be such thatthe change from a broken to a closedmainworkingcircuit, or vice versa, should be made a brief instant oftime before the pallet arrives at the bottom of a tooth.

The connection of the pallet and escapementwheel with and their mode ofoperating an ivory roller whose periphery has strips ot'metal letinto itare hereinafter particularly described.

,The adjustment of the pallet and'theformation of the teeth of the wheelare represented in. Fig. 4. of the drawings, theteeth being soconstructed that by the alternate back-andforth movement of the twopallets against them. there shall be produced a constant intermittentrotary movement of the escapementwheel. These pallets are drawn awayfrom theteeth by the action of electro-magnets M N, one for each palletor lever of the said pallet,

and made to act against the said armature that projects from said leveror is connected therewith, as hereinbefore mentioned.

The two electro-magnets belonging to the two pallets of each of the twosynchronous machines are operated by one of two local batteries, O 0,one of which is situated at one terminus of the telegraphic line, whilethe other is situated at the other terminus thereof. The electriccurrent of either of the said batteries is alternately directed toeither one or the other of the said magnets by the motions of thearmature of the main-circuit' nagnet P.

In the 'drawingslhave represented the main or primary writing line orwire of the telegraph at Q, said wire being supposed to be extendedbetween the two stations and to be connected with two brass plates, SS,of the two synchronous machines by means of screw-cups, as seen at. b c.The other or secondary vire,

or that of the main line for working, is seen at R as extending. betweenthe two stations and connected with the wooden bases T T of thesynchronous machines by screw-cups d e.

The arbor f of the escapement-wheel is in electric connection with:themain communication-wire Q, as the frame or part G, within which saidarbor is supported, rests on the metallic plate S.

0n the arbor of each escape-wheel of each machine there is fixed anivory roller, U, which has seven'narrow strips of silver, (or other.metalnot easily oxi'dizable,) g g g let into its cireumference'at equaldistances apart, each of said strips beingin electric connection withthe arbor by being joined to a metallic disk or plate, E, that is fixedon the arbor and'at the outer end of the roller or cylinder U. The widthof each of the metallic strips may be about the one twenty-eighth partof the entire circumference of the ivory roller U. Near this roller areadjusted four springs, V WX Y, whose ends are bent downward and made tobear against the external curved surface of the roller U. The said bentends are so arranged at such distances apart that during the rotation ofthe roller they shall be successively brought in contact with each oneof the metallic strips extending across it.. If these four springs beput in connection by means of wires 1 2 3 4 or 1 2 3 4 with fourregisters or suit able apparatus for telegraphic correspondence by therotation of the roller U, they will be brought into successiveconnection with the arbor and of course the common wire Q.

On the other end of the arbor above mentioned is another ivory roller orcylinder, Z,

which bears fourteen strips, hit, of silver or metal, extendingtransversely across its curved periphery or surface and let into thesame and at equal distances apart, the width of each of the said stripsbeing made to correspond with that of the space of ivory between any twoof them. The external curved surfaces of the strips are in the surfaceof the cylinder. Two springs, t k, are adjusted over this roller, theirends being bent down so as to rest upon it, and to press upon the samepiece of silver or any division of the ivory at one and the same time.These springs, as well as the others hereinbefore mentioned, are allinsulated by being supported by pins Z l I, that extend through a pieceof ivory, m, that is let into the upper part of a post, a, which risesup from the platform '1.

Thereis an apparatus, called a switch, used for establishing a metallicconnection between the two springs tic, independent of the connection bya strip of silver on theivory roller, so that when the two springs maybe resting on a division or space of the ivory roller or cylinder Z wemay be able to put the springs into electric connection. This switchconsists of two pieces of metal, 0 19, one of which is fixed to and madeto project from the pin or wire that supports one of the springs i k,while the other turns vertically on the pin or wire that supports theother of the said two springs.

When the turning piece is moved so as to be carried in contact with thestationary piece, an electric metallic connection between the two pinswill be established. One of the springs, t k, of each synchronousmachine, by means of a wire, 1, is made to extend to the screw-cup d ore of the main working line or wire R, and thus an electric connection isestablished between one'of the springs 45 k of one machine and one ofthe springs t' 70 of the other. The other spring of each set of twosprings i k belonging to the two machines is put in connection with oneend of the wire of the maincircuit magnet P of each. machine, while theother end of such wire leads to a screw-cup, q, that connects with abattery, A there being such a battery at one or both of thetcrminiof thetelegraphic line. From the opposite end of each of these batteries awire, r, leads to a plate of metal, 3, sunk in the earth at the stationof each synchronous machine, the ground between the two plates 8 8serving to complete the circuit between the two batteries A A Two otherscrew-cups, t u, are placed on the platform T of each synchronousmachine, and

are respectively connected with the wires 11 w of the local battery 0 or0. One of these cups-viz., the cup t of each synchronous machine-bymeans of a wire, at, is put in connection with the armaturey of theadjacent main-circuit magnet, (the other cup, 20, being connected withthe electro-magnets M N by the wire ta The said armature swings orvibrates on a pin, 2, and in direction toward and away from the poles ofits circuit-magnet. Itswings between two screws, a b, which arerespectively connected with the two local magnets by means of wires 0 d.A spring, 6, is applied to the armature and to the main framework of themachine and made to operate in such manner as to draw the lower part ofthe armature against the screw on when the elec tric current ceases toflow through the circuitmagnet P. When the electric current does flowthrough such circuit-magnet the armature is drawn toward the magnet andin. contact with the other screw, 1); and thus it W be seen that bymeans of such movements of said armature the two local magnets will bealternately charged by the local battery at the station, the detents ofthe escapement-wheel bein alternately operated by the charging anddischarging of said local magnets.

From the above it will be observed that if there is any play to thearmature of the maincircuit magnet only one of the local magnets can becharged at a time.

The several parts are so adjusted that when the batteries are attachedand the main circuit closed its armature, being attracted toward it,will close the circuit of the proper local magnet, so as cause the sameto draw its own detent or pallet away from the escapemcnt-wheel, andthereby leave the other to act upon the wheel and impart to such wheel arotary motion until the pallet reaches the bottom of the angular spacebetween the two teeth between which it may be working. This actionbrings the ivory roller Z into such position that its two springst' Itwill rest on an ivory interval or space of the wheel, At this time oneof the four springs before spoken of as applied to the ivory cylinder Uwill rest upon one of the metallic strips of said cylinder and be inelectric connection with the arbor of the cylinder. It, now, the maincircuit be opened by means of the switch which connects the twospringsik, these two springs, resting on ivory, leave the circuitbroken. This done, the armature of the main-circuit magnet flies back,and. thereby breaks one local circuit and closes the other. 7 The localcircuit which is now closed withdraws its own detent from the wheel whenthe other detent rests on and near the middle of its tooth, which lastmentioned detent, by the action of its spring, is caused to impartrotary motion to the escape-wheel to the extent sutiicient to to bring astrip of silver of the wheel Z directly under and in contact with thetwo springst'k ot' the main operating circuit or wire 1%, so that thiscircuit is again closed and a different one of the four springs isbrought into connection with the main writing-circuit by means of one ofthe seven strips of silver of the wheel U, The main operating-circuit Bbeing closed by this position of the escape-wheel, the armature of themain-circuit magnet is drawn forward and again closes the circuit of thefirstnamed local magnet, whereby another motion of the wheel takesplace, so as to bring the third one of the four springs into electricconnection with the arbor of the escapement-wheel, and the maincircuitis again broken. Thus a rapid rotation of the escape whecl iskept up so long as the connection is kept broken at the switch, bringingthe four springs into successive connect-ion with the arbor, and ofcourse with the main line with which it is connected.

The several wires 1 2.3 4 or 1 2' 3' 4 that connect with the set of foursprings of the closed.

wheel Z of each synchronous machine also connect with one pole of abattery, B, disposed at each station or end of the line, which batteryis connected with the ground by means of a metallic plate, D and wire Owhereby the main.writing-circuit Q is completed.

There is a spring thumb-lever, E having a stop, F, applied to the postor frame that supports the arbor of each escape-wheel, the

stop being arranged so as to act in connection with another stop or pin,H that projects from-the side of the escape-wheel. When the thumb-leveris pressed in a direction toward the-arbor of the escape-wheel the stopH" (durin g the rotation of the escape-wheel) will come in contact withthe stop of the thumb-lever, so as to arrest the rotary motion of theescapement-wheel. These stops and thumb-lever are for the purpose of'detainin g the wheel at pleasure, in order to enable us to adjust thetwo synchronous machines so that they may properly start together,provided one of them should get out of adjustment, it being understoodthat when any one of the four springs of the wheel U ofone machine is incontact with one of the strips of silver of such machine thecorresponding spring of the other machine should be in like contact witha strip of silver of its wheel U.

The mode of regulating the two machines when one gets out of adjustmentas above stated may be thus described: While operating thetelegraphing-line the switches of all but one of the machines in thecircuit are kept That which has its switch'not closed may be termed thedriving-machine, and it may be any one selected at pleasure, accordingto circumstances. When one of the machines is discovered to be out ofadjustment, the per: son who has charge of it instantly breaks thecircuit. This stops the motion of all the machines. The circuit beingbroken in two places at a time, and the machinery having the power toclose only one of them, this signal will be understood by the person whohas charge of the driving-machine as a notice that some one wishes toadjust. The person who broke the circuit next closes it and immediatelypresses on the adjusting thumb-spring. This arrests :the motion of hiswheel when.the pin in the wheel comes in contact with the thumb-lever.The person in charge of the driving-machine now presses upon histhumb-lever, and presently his wheel stops, and all the others stopalso. The person who wishes to adjust immediately lets go histhumb-lever, and the one havi'ng charge of the driving-machine lets goof his thumb-lever an instant afterward, and thus the machines start inunison. In practice this operation can be performed in less than twoseconds. Provided the rotation of the escape-wheel is rapid-say aboutone hundred and fifty times per minuteit will bring each of the foursprings into com um unication'with the main writing-wire about eighteentimes per second. It, now, there were'a battery upon the mainwriting-wire and there were a register connected with each of the foursprings of the cylinder U, and also with the ground, and it this werethe ca-se at both ends of the line, there would be about eighteen dotsper second recorded by each of the registers; but they would not be madeby any two registers ,at one end of the line at precisely the sameinstant of time,the dotofoneinstrument being completed before the otheris commenced. Suppose the register-paper upon which the telegraphicmessage is to be recorded-moves at the rate of one; half inch persecond, the dots made upon it would be in-number thirty-six per inch,and ranging in line with one another. This would be'near enough to acontinuous line for telegraphic purposes, and if the short or branchportions of the circuit were broken and closed by a key, as in ordinarytelegraphic manipulations, groups of dots would be produced, whichgroups would correspond to the dashes or lines usually made on theregister-paper, short groups answering for the dots and longer groupscorresponding to the dashes or lines of ordinary telegraphic characters,as will be seen in Fig. 7, wherein the groupings of dots are made toexhibit the same signs as do thclines under them.

From the above it will be seen that four per" sons could be engaged atthe same time in transmitting correspondence over the same wire and indifferent directions, though only one was actually using the current atthe same instant.

I do not, of course, limit my invention to the use of four branches onlyat each end of the main line, as any other suitable number ofbranchesfrom two upward may be used, the mechanism being constructed onthe above-describedprinciple and in accordance with the number ofbranches or registers to be used at each. terminus of line. This willall be readily understood by telegraphic operators skilled in the art.

The telegraph-lines, as usually worked, are limited in their operationin either direction to the performance of a single operator on a singlewire or circuit, and thus every line or circuit is limited in itsaction, and if more business is required to be done than can beaccomplished by a single operator on such circuit, it becomes necessarythat an additional circuit or wire or line of telegraph be employed.

Now, it will be seen from what has been above set forth that by myinvention I am enabled to increase the powers of a single line oftelegraph or circuit to a very great extent after I have appliedto itanother line or circuit, which I have hereinbel'ore termed the secondaryor main line" of working, for by myimprovementsI am enabled to double,triple, quadruple,or'still further increase the power of such line oftelegraph.

It is not necessary that the branch lines should all be in one oflice orstation of the terminus; but they may" separate and have their membersor parts as hereinbefore described,-

and as represented in the drawings, but intend to vary the form of anyone or more of such parts, or to make use of instead of the same anymechanical or electrical equivalent therefor, while I do not change themain principle or character or combination which constitutes my saidinvention; nor do I limit inyinvention to the methcd above described ofactuating or putting in motion the escapement-wheel, but employinsteadthereof any well-known method of giving it a tendency to rotate,provided its rotation be controlled by an electromagnetic escapement;neither do I limit myinvention to the method herein described'ofbreaking and restoring the main operating-circuit, but use instead acircuit-'breakin g wheel propelled by power or any known and convenientmode of breaking and closing the main circuit with I greater or lessrapidity at pleasure.

What I claim as myinvention is The method hereinabove described ofbringing any number of telegraphic, signali zing, and recordinginstruments into successive electric connection with the common communicating-wire, meaning more particularly to claim the combination ofthe writing and working or primaryand secondary circuits, theelectromagnets, and movable armatures of the primary circuit, the localmagnets and their movable armature, and pallets or equivalents therefor, and local battery and battery-connections of each terminus, andconnections leading to the armatures-of the local magnet, theescapernent-wheels, and wheels U and Z on thearbor of each, the twoseries of springs of said wheels U and Z, and branch connections, andthe branch connections of the main writing-circuit at its two termini,the whole beingconnected and made to operate together substantially asdescribed.

In testimony whereof I have hereto set my signature this 13th day ofAugust, A. D. 1852.

' MOSES G. FARMER.

Witnesses.

R. H. EDDY, FRANCIS GOULD.

